My son has a 04 Mustang V6 3.9L. He wants to replace the the exhaust system, so I have been trying to help him. At Planet Magnaflow I found a system P/N 15717 that indicates it is for the 04 V6 3.8L. My question is this, do any of you know if the 3.8L and the 3.9L systems are interchangeable? I do not know what the differences between these two motors are and do not want him to order something that will not fit and then have to pay a restock charge to return it.
Thanks for your help,
Lon